1821566649460 has 24 divisors (see below), whose sum is σ = 4050307021320. Its totient is φ = 685766267904.

The previous prime is 1821566649439. The next prime is 1821566649491. The reversal of 1821566649460 is 649466651281.

It can be written as a sum of positive squares in 4 ways, for example, as 811228065124 + 1010338584336 = 900682^2 + 1005156^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1821566649395 and 1821566649404.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2678774145 + ... + 2678774824.

It is an arithmetic number, because the mean of its divisors is an integer number (168762792555).

Almost surely, 2^{1821566649460} is an apocalyptic number.

1821566649460 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1821566649460 is an abundant number, since it is smaller than the sum of its proper divisors (2228740371860).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1821566649460 is a wasteful number, since it uses less digits than its factorization.

1821566649460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5357548995 (or 5357548993 counting only the distinct ones).

The product of its (nonzero) digits is 14929920, while the sum is 58.

The spelling of 1821566649460 in words is "one trillion, eight hundred twenty-one billion, five hundred sixty-six million, six hundred forty-nine thousand, four hundred sixty".